Muhammad Ali battled Parkinson's disease for several years before his death. Actor and activist Michael J. Fox, who also has Parkinson's, talked with NBC10's Aundrea Cline-Thomas about an emotional phone call he shared with the legendary Ali about the disease. Both have been active advocates for Parkinson's awareness. (Published Sunday, June 5, 2016)

Michael J. Fox remembers how it took him a couple days to build up the courage to return a voicemail left by Muhammad Ali.

Even after he was finally prepared to call back one of the most famous men on Earth, Fox said he ran into a bathroom so nothing would distract him.

"It took me a couple of days to return the call because I just, he's such a hero of mine, I didn't know what I would possibly have to say to him," Fox told NBC10 in an interview Saturday afternoon while visiting the Wizard World convention in Center City. "So I took the call in my bathroom because I wanted some privacy. And I had three kids running around at the time. I didn't want any distractions."

The conversation happened shortly after Fox was diagnosed with Parkinson's disease, an incurable, degenerative illness, in the early 1990s. Ali had been diagnosed nearly a decade earlier in 1984.

Fox announced his Parkinson's affliction publicly two years later in 1998, and while the two did work together to raise awareness, the "Back to the Future" star took the mantle as the public face for the disease over the last two decades.

"Fighting in Congress with him was an amazing experience," Fox said. "He didn't have that ability to communicate very well, so he had somebody read his words. But he knew it was his belief and his ambitions that were being represented."